A comprehensive approach for preventive and corrective control to mitigate voltage collapse

This paper deals with determination of preventive and corrective control strategies to contain voltage collapse in stressed power systems. For cases with insufficient voltage stability margin, the margin sensitivity is first computed to identify the most effective preventive controls, then a linear optimization with the objective of minimizing the control cost is performed to coordinate the control actions. For cases when no steady-state equilibrium point exists, mostly resulting from severe contingencies, a parameterized control strategy is first utilized to restore the system solvability. Then, the continuation method is applied to compute the corresponding minimum corrective control actions. The control measures consist of rescheduling real power generations, implementing generator secondary voltage controls, switching on shunt capacitors and shedding loads. Case studies with the New-England 39-bus system are presented to illustrate the approach.